Management Recommendations for Restoring Cedar Mountain Aspen

Aspen clones of an aspen-dominated community on Cedar Mountain in southwestern Utah are deteriorating, some having experienced high mortality coupled with insufficient regeneration. The objectives of this study were to (1) determine if decadent, non-regenerating mature aspen stands could be regenerated by clearcutting; (2) determine the extent of ungulate use of regenerating aspen ramets; and (3) develop management recommendations. Clearcuts were made in late summer of 2001 in 10 different clones that exhibited various levels of decline on a continuum from relatively healthy to extremely deteriorated. Nested wildlife/livestock exclosures were constructed in each clearcut plot, as well as in a corresponding uncut control plot. In the fall of 2002, regenerating suckers were counted. In addition, vigor and ungulate utilization of these suckers were measured in the wildlife and livestock exclosures, as well as in an unprotected portion of the clearcut and control plots.

Regeneration of the clearcut plots ranged from none in the most decadent clones, to 75,000 stems/ha in the least decadent clone, and was significantly greater than the control plots. Greenhouse trials found no difference in regenerative abilities between clones, however regeneration success in the clearcut plots was significantly related clone basal area prior to treatment. Vigor, as measured by height of the suckers, was 1.5 to 2.1 times greater in the clearcut plots than in the control plots. Seventy-three percent of the suckers in the unprotected portion of the plots were heavily browsed, while only 12% were not browsed. As a result of severe decadence and browsing pressures, which may limit the clone’s ability to successfully restock and remain on the landscape, management recommendations for Cedar Mountain aspen clones were developed utilizing regenerative status, basal area, and browsing pressure.